Stringer - person mostly running the bands over the pins
Holder - person mostly holding the cages
inner cage - the inside piece which holds the mic        
outer cage - the outside piece which attaches to the mic stand

Holder puts inner and outer cages together in mid-air, as close as possible to their final position.  
The inner and outer pins should be turned such that they are evenly spaced apart.
Stringer establishes an outer pin as the fixed tension point and hooks the band around that outer point first
The stringer instructs the holder to hold and guard that point.
Holder begins not only holding the pieces together, but also keeping tension between the cages.
Holder needs to keep the pieces straight and at the correct distance.
Stringer, being responsible for the string tension, begins hooking along the hemisphere, alternating inner and outer pins until the band is installed.
With the slack all used, the stringer no longer needs to apply string tension and all tension falls on the holder and the intra-cage tension.
The stringer is now free to pick up and apply the second band.
For the second band, the stringer should hold and guard the first point and maintain string tension.